The present invention is based on a dual-circuit pressure medium brake system and method with dual-circuit pressure medium storage and with a dual-circuit control valve as well as with a relay valve intended for each brake circuit, where the storage pressure is available and which can be controlled by the dual-circuit control valve. Such a brake system is known (German Patent Application No. W 10827).
In such a known brake system the relay valve can only be controlled by a single circuit. In case of a defect in the control circuit this may lead to a loss of the braking pressure.
It is further known already to provide in one of the two circuits of a dual-circuit pressure medium brake system additional control elements, as for instance a load-dependent brake pressure control (German Offenlegunsschrift No. 19 46 446). However, because of the loss of time in one of the brake circuits a simultaneous brake pressure metering in both brake circuits cannot take place.